The present invention relates to a device which is useful for efficiently extending and retracting a wide variety of tools and, more particularly, to a device made up of a plurality of interacting members which can be easily extended and retracted so as to place in the desired location a tool or other instrumentality attached to the device.
It is often desirable to be able to place and cause to operate a tool or other instrumentality (hereinafter "tool") at a location which is more distant than can be comfortably reached by extending one's arm with the tool therein. For example, when one wishes to change an incandescent light bulb located in a ceiling which is ten feet tall, it is necessary to grab and rotate the light bulb. To this end one might climb on a ladder and use one's hand to replace the bulb. Alternatively, one could obviate the need to use a ladder by using a sufficiently long pole which had a tool at its end which was capable of grabbing and rotating the bulb. In this case, the operator would remain standing safely on the ground while replacing the light bulb and would carry out the operation through the use of the long pole.
While a pole as described is useful in certain application, it is not free from shortcomings. Primarily, it is known that, unlike the case of replacing a light bulb described above, in many operations the location at which the operation is to take place is not at a fixed distance from the user but varies either discretely or continually during the operation.
For example, if one wished to paint the ten-foot tall walls and the ceiling of a room with a paint roller, means must be at hand for locating the roller at every point on the walls and ceiling. Furthermore, the location of the roller varies instantaneously during each painting stroke, regardless of the position of the painter. One option is to use a hand-held roller and make use of a ladder or scaffolding to reach the top portions of the walls and the ceiling. Another alternative is to mount the roller on a sufficiently long pole which will allow the top portions of the walls and the ceiling to be reached with the painter remaining standing on the floor without requiring the use of a ladder.
One disadvantage of this technique is that the length of a stroke is limited by the distance through which the painter's arms can move, i.e., if the painter is able to translate the pole a distance of three feet, the paint stroke on the wall will be limited to three feet.
A further disadvantage of this technique is that the pole is of fixed length and may therefore be of limited use in other applications. Thus, a five foot pole which may be useful in painting a room having ten-foot high walls and ceiling, may be largely inadequate in painting a room having fifteen-foot high walls and ceiling.
To partially overcome the latter disadvantage and to thereby increase its versatility, it is possible to form the pole from a number of detachable modules. In this way modules could be added or removed before each use so as to produce a pole with overall length which is adequate for the intended task. While the modularization of the pole overcomes certain difficulties, it remains a tedious chore to add or remove modules before each task. More importantly, once a pole of proper length has been assembled, it continues to suffer from the disadvantage described above relating to the limitation on the length of the stroke.
A possible solution is to form a pole made up of a number of interconnected members which are able to move relative to one another and thereby alternately lengthen and shorten the pole. Such a pole may use hydraulic or pneumatic means, not unlike those used in a variety of winches, for example, the system used to position a basket carrying an electrical repairman sufficiently near a transformer as to allow the repairman to work on the transformer. However, such systems are heavy and mechanically complicated and are thus not suitable for a simple hand-held pole for use in properly locating a relatively light tool.
There is thus a widely recognized need for, and it would be highly advantageous to have, an extendible-retractable device which can be actively and positively extended and retracted, as desired by the user, with the device oriented at any angle, to which a tool could be attached and which could be easily used to rapidly vary the length of the pole during the performance of a particular task.